As disclosed in Japanese Patent Laying-Open No. 2013-154815 (document 1), Japanese Patent Laying-Open No. 2013-146154 (document 2), Japanese Patent Laying-Open No. 2013-146148 (document 3), Japanese Patent Laying-Open No. 2013-110822 (document 4), Japanese Patent Laying-Open No. 2013-126327 (document 5) and Japanese Patent Laying-Open No. 2013-172116 (document 6), a power receiving device and a power transmitting device which transmit and receive electric power contactlessly are known. For example, document 1 (see FIG. 9) discloses a power receiving device including a power receiving unit, that comprises a shielding casing opened downward, a lid made of resin provided to close the opening of this shielding casing, a core unit which has a ferrite core provided inside the shielding casing, and a power receiving coil wound around this core unit. The power transmitting device also has a similar configuration. Document 6 discloses a power transfer system in which a power receiving device and a power transmitting device include a shield in order to suppress an externally leaking electromagnetic field.
For example, the shield adopted for this power receiving device has a generally box shape surrounding a power receiving coil and also having an opening opened downward (toward the power transmitting device). The shield adopted for the power transmitting device has a generally box shape surrounding a power transmitting coil and also having an opening opened upward (toward the power receiving device).